Slip clamp



SLIP CLAMP Filed July 29', 1930 INVENTOR M4025 ZQ YhFM m Patented Jan.9, 1934 UNITED STATES PATENT v OFFlCE SLIP CLAMP New York ApplicationJuly 29, 1930. Serial No. 471,558

11 Claims.

This invention relates to clamps for electrical conductors andparticularly to slip clamps.

Transmission lines have consistently grown much heavier during the lastseveral years and these heavy conductors require much larger and moreexpensive structures for their support. A large part of the expenseinvolved is due to the necessity for designing the structure withsufficient strength to support itself against the heavy load imposed ina longitudinal direction when one or more of the conductors break. Theseconductors, in extreme cases, have a strength in the neighborhood of40,000 pounds and are strung with tensions up to about half this amount.The maximum load on the structure occurs relatively infrequently and maypossibly never occur, but nevertheless the structure must be able totake care of such loads.

One object of my invention is the provision of a clamp adapted to takecare of excessive loads.

Another object is a slip clamp whose clamping action is automaticallyreleasable upon abnormal conditions of stress in the conductor at oneside of the clamp.

A further object is to provide a clamp with trip washers adapted torelieve the conductor passing through the clamp of clamping action.

A still further object of my invention is to provide a clamp by means ofwhich a tremendous leverage can be secured about the trunnion of. theclamp whereby the washer can be forced to slide against the friction ofthe bolting.

Another object of my invention is to provide a clamp which need not bemade with a high degree of accuracy and which will receive cablesvarying as much as 25% in diameter.

Another object is to provide'a slip clamp which is convertible to anon-slip clamp merely by removing the trip washers.

Other and further objects will be understood by those skilled in thisparticular art or will be pointed out hereinafter.

In the accompanying drawing:

Figure 1 is a side elevational view of a clamp embodying the presentinvention, parts being broken away for clarity; and

Fig. 2 is a view at right angles to Fig. 1, also having parts brokenaway.

Similar numerals refer to similar parts throughout the several views.

The general features of the clamp illustrated are the same as those ofmy copending application Serial No. 471,555, filed July 29, 1930, forsuspension clamps, and includes a body member 10 in the form of aU-shaped groove having upstanding side walls 11 and a centrallydepressed or cut-out portion 12. The body member also has astrengthening rib 13 extending downwardly from its under surface and theapertured ears 0 14 on either side of the central cutaway portion andextending substantially laterally.

Cooperating with said body member is. the keeper member 15 having agroove opposite that of the body member so as to form a circular pas- 5sage 16 for a conductor or the like. Extending from the keeper memberare the downwardly extending bolt members 17 which pass through theapertured ears 14 in the body member. The central portion of the keepermemberis contoured convexly and is provided with pear-shaped trunnions18 as shown, over which are irremovably sprung the arms 19 of the yokeor clevis member 20, as understood from my copending application. In theinstance shown, the upper end of the yoke or clevis member is providedwith a socket member 21 by means of which the same may be hung from astring of insulators or any. other support. As shown in dotted lines, asuitable plate may be provided for making a lateral 30 connection of theclamp to a laterally disposed support.

The yoke arms 19 are provided with extensions or fingers 22 which areshaped as shown in Fig. 1. These fingers are inserted in a slot 23 intrip 5 washer 24, which, as shown, is placed on the bolt members 17between the apertured cars 14 and the nuts 25. The construction of thistrip washer is clear from the drawing and it will be noted that the slot23 is of greater extent than the thickness 99 a of the fingers 22,thereby allowing a certain amount of play or freedom of movement so thatthe whole yoke can pivot or swing a certain amount before the fingerscome in contact with the trip washer.

Additional trip washers 26 are used and these latter are similar washersabout the size of the nuts 25, but formed with a central upstandingprojection 27, having a flat upper surface and which contacts normallywith the lower fiat simi- 19g lar surface of the downwardly extendingprojection 28 of the first trip Washer. These projections as alreadystated and as shown in Fig. l are normally in contact and keep the partsin the position shown. In the event that the conductor 5 becomes brokenon one side of the clamp or an exceedingly heavy load is placed only onone side of the clamp, an angular motion of the yoke occurs relative tothe keeper member whereby the yoke rotates somewhat about the trunnionscausing, under proper circumstances, the fingers 22 to come in contactwith the trip washer as will be understood clearly from Fig. 1. Thisforces the trip washer longitudinally sliding its downwardly extendingprojection 28 relative to the projection 27 on the other trip washer 26.If the movement is enough, that is, if the forces setting up themovement are strong enough, these two projections will override eachother and become horizontally aligned and the whole body member willdrop relative to the keeper member a predetermined amount, which in thepresent case, would be the thickness of one of the projections 28 or 2'?on the trip washers l4 and 26. This relieves the cable of all clampingand permits it to slide relatively freely through the hole 16 betweenthe body and keeper members, thus relieving the structure from which theclamp is supported from undue longitudinal stress.

The downwardly extending bolt members 17 are unitary with the keepermember as are the apertured ears 14 unitary with the body member. Saidbolts pass through said ears and on the lower ends of the bolts the nuts25 and locking members 29 are placed in the usual manner. The extremeends of both the keeper and body members flare slightly for the purposesexplained in my aforesaid copending application. Suitable lock washers30 may, of course, also be used in addition to the locking members 29,which in this case, may be suitable cotter pins or other locking pinsextending through the ends of the bolts which may also be provided withthe guide tips 31 as understood from my copending application.

The slip clamp as above described and illustrated may, if so desired, beconverted to a nonslip clamp, merely by removing trip washers 24 and 26whereby there is secured. a clamp along the lines of that of mycopending application. Conversely, suitableclamps of the non-slip typemay be converted into slip clamps according to the present invention bythe appropriate provision of trip washers 24 and 26.

Various modifications and substitutions of the various elements can bemade, without departing from the spirit and scope of this invention aspar: ticularly delineated in my aforesaid copending application.

I claim:

1. In a cable clamp having body and keepei members and means forsecuring them together so as to clamp a cable therebetween, a tripwasher, having a slot therein, interposed in said securing means, and aportion of said clamp projecting into said slot adapted to actuate saidwasher to cause the same to drop downwardly and thus to release clampingpressure on the cable within the clamp.

2. A clamp comprising a body member, a keeper member associatedtherewith, trunnions on said keeper member, a yoke sprung over saidtrunnions, means for securing said keeper and body together, a tripwasher interposed in said securing means, having an aperture, a fingeron said yoke member projecting into said aperture, a second trip Washercontacting with saidfirst washer, and means for disengaging saidwashers.

3. In a clamping construction, a plurality of trip washers havingcontacting projecting portions, and means to disengage said portionsthereby releasing clamping pressure on a mem ber within said clampingconstruction.

4. In a clamp having a body member and a keeper member bolted togetherin clamping relationship, a trip washer associated therewith, a secondtrip washer engaging said first trip washer, and means for automaticallydisengaging said washers under abnormal conditions to relieve theclamping pressure on a member within said clamp.

5. A slip clamp adapted to conform to abnormal conditions including aplurality of trip washers relatively slidable under said abnormalconditions, and means actuated by said abnormal conditions to effectsaid sliding action.

6. A slip clamp adapted to conform to abnormal conditions including aplurality of trip washers having relatively slidable contactingprominences, and means for aligning said prominences and thus relievingclamping pressure on a member within the clamp.

'7. A clamp consisting of upper and lower clamping members, meansirremovably associated with said upper member for suspending said clamp,means for clamping a tension member within said clamp, and trip washermeans relatively slidable under abnormal conditions for automaticallyreleasing said tension member from clamping action.

8. A clamp consisting of upper and lower clamping members for a tensionmember, trunnions on said upper member and a suspending yoke irremovablysprung over said trunnions, nut and bolt means on said members forsecuring a clamping action on said tension member, and relativelyslidable trip washer means intermediate of said bolts for automaticallyrelieving said tension member of clamping action upon abnormalconditions existing on one side of said clamp.

9. In a cable clamp of the class described, means for maintaining acable normally clamped therewithin, and means for automatically andpermanently releasing the clamping pressure on said cable under abnormalconditions, said last means including a slotted trip washer which dropsto a lower level and introduces a corresponding freedom of movement intothe cable clamping means.

10. In a cable clamp of the class described, means for maintaining acable normally clamped therewithin, and means for automatically andpermanently releasing the clamping pressure on said cable under abnormalconditions, said last means including a slotted trip washer interposedin the normal clamping means and adapted to permanently release thenormal clamping pressure under abnormal conditions.

11. In a cable clamp of the class described,

means for maintaining a cable normally clamped therewithin, and meansfor automatically and permanently releasing the clamping pressure onsaid cable under abnormal conditions, said last means including a tripwasher which, when interposed in the normal clamping means, provides aslip clamp and which, when not so interposed, provides a non-slip clamp,the conversion from former to latter being effected by removal of saidtrip washer from the cable clamp assembly.

RALPH L. JENNER.

